A sphere is a three-dimensional figure. Three-dimensional geometric figures: All kinds of figures abstracted from physical objects are collectively called geometric figures, and geometric figures are one of the main objects of mathematical research. Some geometric figures (such as cuboid, cube, cylinder, cone, sphere, etc. ) are not on the same plane, they are all three-dimensional graphics.

Interpretation of the concept of sphere

Definition: A figure composed of all points whose distance from a fixed point in space is less than or equal to a fixed length is called a ball.

Description: Sphere is a three-dimensional figure with continuous surface, and the geometry surrounded by sphere is called sphere.

There is no absolute sphere in the world. Absolute spheres exist only in theory.

But in a weightless environment (such as space), the droplets will automatically form an absolute sphere.

General reference; Refers to spherical sporting goods and ball games, including handball, basketball, football, billiards, volleyball, badminton, tennis, golf, ice hockey, beach volleyball, baseball, softball, rattan ball, shuttlecock, table tennis, billiards, kicking, cricket, squash, casserole, curling, croquet, rugby and hockey.